Fastening device



May 5, 1964 3,131,397

W. S. MILLER FASTENING DEVICE Filed April 30, 1962 i 2a 9!? 5 111.6 [4 :7 9 H wENDELL S. MIL-LEE IN VEN TOR.

ATTORNEY United States Patent 3,131,397 FASTENING DEVICE Wendell S. Miller, 1341 Cornstock Ave, Los Angeles, Calif. Filed Apr. 30, 1962, Ser. No. 191,058 Claims. (Cl. 1-49) This invention relates to an improved device for driving a fastener into a work piece. In the form of the invention typically illustrated in the present application, the invention is shown and described as applied to a stapling unit, for driving staples into a piece of wood or other material. However, it will be apparent as the description progresses that the features of novelty of the invention are also applicable to devices for driving other types of fasteners, such as nails, tacks, or the like.

The fastening devices with which the present invention is concerned are of the general type in which the staple or fastener is driven by a hammer or driving element which is urged with substantial force in its driving direction by a spring or other yielding means. In such devices, suitable means are normally provided for retracting the driving element, against the tendency of the spring or other yielding means, and then suddenly freeing the driving element to impact against a staple or other fastener and thereby drive the fastener into a work piece.

In using a conventional device of the above discussed general type, as heretofore constructed, it is necessary for the operator to exert a rather strong force against the device if he wishes to make certain that the staple or other fastener is driven properly into a work piece. If this force is not exerted by the user, the stapler or other device will usually fail to drive the fastener as far into the work piece as would be desired, and therefore will leave the staple in a condition in which it projects outwardly too far from the wood and is ineffective for securing a piece of paper or other second work material to the main work piece. The general object of the present invention is to overcome this defect of conventional fastening devices, by providing a device which will reliably drive a staple or other fastener to a predetermined fully installed position within a work piece, without the necessity for exerting the discussed force against the device.

I have discovered that this failure of conventional stapiers to drive a staple fully into a work piece is not usually due to insufficient strength in the driving spring, but rather is caused by a recoiling action of the main body of the stapler, wmch action causes the stapler to retract slightly away from the work piece during the driving stroke. The above discussed strong force which must be exerted by the user is required in order toprevent such recoiling movement. In the present invention, I overcome this difiiculty in a very simple manner, by providing an arrangement in which the slight recoiling movement of a portion of the stapler is not permitted to affect the depth to which the staple is driven relative to a work piece. More specifically, I provide a stop structure for limiting the driving motion of the hammer or other driving ele ment, and I so mount this stop structure that the recoiling force exerted by the spring or other yielding means is not transmitted to the stop structure. Instead, the recoiling force exerted by the spring or its equivalent is taken by a backing element which is free for retracting or recoiling movement relative to the mentioned hammer-stop structure during a driving operation. The backing element may be, and preferably is, connected to the main handle body of the stapler, so that the entire body recoils with the backing element and relative to the stop structure, to effectively absorb the entire reactive force. In the optimum arrangement, the stop structure is carried by and is mounted for movement with the usual staple carrying magazine. This magazine and the stop structure may be 3,131,397 Patented May 5., 1964 connected to the rest of the stapler by a simple pivotal connection, which by very slight limited pivotal movement attains the highly desirable recoil counteracting effect discussed above.

The above features and objects of the present invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawing, in which:

FIG. 1 is a perspective View of an impact type stapler constructed in accordance with the invention;

FIG. 2 is a side View of the FIG. 1 stapler, partially broken away to reveal the inner mechanism;

FIG. 3 is a vertical section taken on line 3-3 of FIG. 2;

FIG. 4 is a horizontal section taken on line 44 of FIG. 2;

FIG. 5 is an enlarged fragmentary vertical section taken on line 5-5 of FIG. 2, but showing the driving element in retracted position;

FIG. 6 is a fragmentary perspective representation of the lower portion of the driving element and the coacting end of the staple magazine; and

FIG. 7 is a fragmentary side view showing the manner in which the body of the stapler recoils away from the work piece while the staple magazine remains in contact with that work piece.

Referring first to FIGS. 1 and 2, I have represented at It? a stapler of the impact type having a main hollow body 11 typically formed of sheet metal deformed to the illustrated configuration. This body may have an opening 12 for receiving the fingers of an operator in use, and may carry an actuating handle 13 which is pivotally connected by a pin 14 to body 11 for manual actuation downwardly from the normal full line position of FIG. 5 to the broken line position of that figure. Such downward actuation of the handle 13 causes the inner mechanism within body 11 to drive a staple into a work piece typically represented at 15 in FIGS. 2 and 7, to which there may be secured by the staple a sheet of paper or other material 16. The handle or actuating lever 13 may be yieldingly urged to its full line retracted position of FIG. 2 by a spring represented at 17, which spring may be coiled about pin 14 within the body, with the opposite ends of the spring bearing against handle 13 and a rigid backing element 18 mounted in fixed position relative to body 11. This element 18 may take the form of a small piece of rigid sheet metal, extending between and rigidly welded or otherwise secured to the opposite parallel side walls 19 of main handle body 11.

The forward side of body 11 may be closed by a separately formed cover 20, which in the illustrated position of the device extends vertically, and which may be secured to the opposite side walls 19 of body 11 by rivets 21 (FIG. 1) extending through side tab portions 22 and 23 of cover 20, and connecting into the side walls 19 of body 11.

The staples are carried by a magazine 24, and are fed,

by that magazine to the left in FIG. 2. Uponeach actuation of the device, the leading staple is driven downwardly by a hammer or driving element 25, whichmay be of the illustrated conventional configuration, and which is typically formed of a piece of sheet metal bent to form a hollow element having the external shape shown in FIGS. 2 and 3. The hammer 25 carries a downwardly projecting substantially rigid finger or plunger 26, for engaging and acting directly against the staples themselves, which plunger 26 may either be an integral portion of the element 25 or be formed separately, as shown, and be rigidly secured to element 25 by a rivet 27 or otherwise. The driving element assembly 25-26 is suitably guided for only vertical movement relative to body 11, along an axis 28, with this guiding being effected by means of two tabs 29 formed on part 25 and slidably received between 3 the forward edges 30 of body side walls 19 and the front wall of cover 20.

The driving element assembly 25-26 is yieldingly urged downwardly by a coil spring 31, centered about axis 28, and acting at its lower end against a bottom wall 32 of element 25, and at its upper end against the backing element 18 (which may carry a centering pin 33). For retracting parts 25 and 26 upwardly in response to downward movement of handle 13, there may be provided any conventional actuating linkage, such as that represented in FIG. 2 at 34. This linkage typically includes a retracting part 35, mounted to pivot about a pin 36 secured to side walls 19 of body 11, and having a finger 37 engageable with a lug 33 formed on part 25, to lift part 25 upwardly upon upward pivotal movement of element 35. The retracting element 35 may be pivoted at 33 to a link 40, which is in turn pivoted at 41 to a first end of a bellcrank 42, which is pivoted at 43 to body 11, and at 44 to a link 45. This link 45 may be pivotaliy connected at 46 to a lug 47 rigidly secured to the inner surface of handle 13. As will be apparent, downward actuation of handle 13 acts through link 45 to swing bell-crank 42 in a clockwise direction, resulting in upward movement of link 40, and upward swinging movement of element 35, to retract driving element assembly 25-26 upwardly. When the parts reach the broken line positions represented in FIG. 2, the lug 37 on part 35 moves slightly out of engagement with lug 38, to free the hammer or driving element assembly 25-26 for rapid downward staple driving movement under the influence of the spring 31. In order to allow lug 37 to subsequently move downwardly past lug 33, in preparation for another stapling operation, the pin 36 may be received within an elongated slot 48 in part 35, so that part 35 is free for rightward retracting movement to pass lug 38, with this movement being resisted yieldingly by a spring 49, whose coiled portion is mounted about a pin 56 and whose opposite ends bear against element 35 and a pin 51. It will of course be understood that pins 50 and 51, like the other body carried pins 36 and 43, may be connected at their opposite ends to the side walls 19 of the body.

Magazine 24 may be of any conventional construction adapted to receive a series of staples 52 and progressively feed those staples to a driving location. As seen in FIGS. and 6, this magazine may include an outer horizontally elongated hollow channel part 53, which may be formed of sheet metal deformed to a generally U-shaped upwardly opening configuration. Within part 53, there may be provided a second horizontally elongated channel shaped guide element 54, also of upwardly opening gen erally U-shaped cross-section. The vertical legs of the staple are then received between the closely spaced vertical side walls 55 of parts 53 and 54, while the upper cross-pieces 56 of the staples are confined between upper edges 57 of part 54 and two inturned horizontal flanges 58 formed by part 53. The staples as thus received within the channel shaped guideway formed between parts 53 and 54 are yieldingly urged to the left in FIG. 2, by the usual sliding pusher member 59 (FIG. 2), which is yieldingly urged to the left by a spring 66 disposed about a guide-rod 61 attached to a member 62 which is connectible into and removable from the right end of the magazine.

At its left or leading end, the magazine 24 is closed by a Wall 63, which preferably extends directly vertically and transversely of the axis 64 of leftward advancement of the staples within magazine 24. Wall 63 may be formed of sheet metal, and be secured to part 53 by tabs 65 turned about the outer sides of part 53 and welded or otherwise secured to that part. Wall 63 is spaced from the end edges 66 of magazine members 53 and 54 a distance corresponding to the thickness of a single one of the staples 52, and corresponding also to the thickness of element 26, so that element 26 may move downwardly within that narrow space and drive the leading staple into work piece 15. In this connection, it is noted that the lower edge 67 of part 26 is parallel to the upper cross-piece portion 56 of the leading staple, and therefore effectively engages that portion of the staple to drive it downwardly.

The entire magazine 24 is mounted to body 11 for limited pivotal movement relative thereto about a pin 63 at the right end of the magazine. This pin is secured to the opposite side walls of the body 11, and may connect to the magazine by extension through openings in two tabs 69 formed by and projecting upwardly above part 53. The pivotal movement of the magazine may be limited by extension of a pin 70 on wall 63 through a vertical slot 71 formed in the end cover 24) of the housing. As seen in FIGS. 1 and 2, the end cover 20 may be bulged outwardly at 72, at a location opposite the end of the magazine, to avoid interference by wall 29 with the vertical swinging movement of the magazine.

The downward driving movement of hammer assembly 25-26 may be limited by engagement of the bottom wall 32 of element 25 with a cushion or pad represented at 73 in FIGS. 2 and 5. This pad may be formed of a piece of leather, plastic material, or any other substance preferably adapted to slightly deform resiliently under the impact of the hammer, to absorb some of the shock from that impact. As seen in the drawings, the stop element 73 is desirably mounted to the upper surface of main magazine part 53, as by extension across the upper sides of inturned flanges 58, with part 73 being bonded or otherwise secured in fixed position relative to those flanges.

To now describe a cycle of operation of the stapler, assume that magazine 24 is properly loaded with staples, and that retaining element 62 and its carried parts are connected into the right end of the magazine and are retained therein by friction or by appropriate latching means (not shown). Also assume that handle 13 is in its upper full line position of FIG. 2, in which position plunger element 26 is received within the space 74 at the leading end of the magazine, and may have its lower edge 67 disposed in horizontal alignment with bottom edges 75 of side walls 19 of the main body part 11, and with undersurface 76 of the magazine. A user may then place the stapler over or against a work piece, with the surface 76 in engagement with the work piece, and with edge 67 of part 26 substantially engaging the work piece. The operator then actuates handle 13 downwardly to its broken line position of FIG. 2, to retract hammer assembly 25-26 upwardly (during which movement edges 75 move into engagement with the work piece), and then suddenly release assembly 25-26 for downward actuation under the influence of spring 31. The upward movement of part 26 moves it to the FIG. 5 position, out of the path of the staples, so that spring 66 may advance the leading staple into a driving position beneath element 26, and so that the subsequent downward movement of assembly 25-26 causes part 26 to engage the leading staple and drive it downwardly into work pieces 15 and 16. The reactive force of spring 31 during a driving operation is exerted upwardly against backing element 18, and may cause that element and the body part 11 to recoil upwardly, as to the position of the body represented in FIG. 7. However, by virtue of the pivotal connection of the magazine 24 to the body, at 68, the recoiling movement is not transmitted to the magazine, and the magazine may therefore remain in engagement with the work material, as will be apparent from FIG. 7. The stop element 73 is not retracted upwardly by the recoiling action, and therefore permits hammer assembly 25-26 to move downwardly until lower edge 67 of element 26 is in alignment with the bottom surface 76 of the magazine, or is in some other predetermined optimum final driving position. Thus, the recoiling action has no effect on the extent to which the staple is driven into the work piece or work pieces,

and the intended result of the invention has been attained.

I claim:

1. -A fastening device comprising means for holding a fastener, a driving element movable in a predetermined first direction and operable by such movement to drive said fastener into a Work piece, yielding means urging said driving element in said first direction to drive the fastener, a backing structure taking the reactive thrust of said yielding means in a direction the reverse of said first d rection, means forming a stop surface limit-ing the movement of said driving element by said yielding means in said first direction, means for retracting said driving element, and means mounting said bacrcing structure for recoiling movement in said reverse direction relative to said stop surface under the influence of said reactive thrust of the yielding means.

'2. A fastening device comprising means for progressively (feeding a series of fasteners to a predetermined driving location, a driving element movable in a predetermined first direction and operable by such movement to drive a fastener at said location into a Work piece, yielding means urging said driving element in said first direction to drive the fastener, a backing structure taking the reactive thrust of said yielding means in a direction the reverse of said first direction, means forming a stop surface limiting the movement of said driving element by said yielding means in said first direction, means for retracting said driving element, and means mounting said backing structure for recoiling movement in said reverse direction relative to said stop surface under the influence of said reactive thrust of the yielding means.

3. A fastening device comprising a magazine for holding a series of fasteners and progressively advancing them to a predetermined driving location, a driving element movable in a predetermined first direction and operable by such movement to drive a fastener at said location into a work piece, yielding means urging said driving element in said first direction to drive the fastener, a backing structure taking the reactive thrust of said yielding means in a direction the reverse of said first direction, means forming a stop surface limiting the movement of said driving element by said yielding means in said first direction, means for retracting said driving element, and means mounting said back-ing structure for recoiling movement in said reverse direction relative to said stop surface and relative to said magazine under the influence of said reactive thrust of the yielding means.

4. A hastening device as recited in claim 3, in which said stop surface is carried by said magazine and transmits the driving force of said driving element thereto.

5. A fastening device comprising a handle body, a. magazine for holding a series of fasteners and progressively advancin g them to a predetermined driving location, a driving element movable in a predetermined first direction relative to said body and operable by such movement to drive a fastener at said location into a Work piece, yielding means urging said driving element in said first direction to drive the fastener, s. backing structure mounted to said body and restrained against movement in said reverse direction relative to the body and taking the reactive thrust of said yielding means in a direction the reverse of said first direction, means forming a stop sur face limiting the movement of said driving element by said yielding means in said first direction and transmitting the advancing force of said driving element to said ma azine, means for retracting said driving element, and means mounting said handle body and said backing structure for recoiling movement in said reverse direction relative to said stop surface and relative to said magazine under the influence of said reactive thrust of the yielding means.

6. A fastening device comprising a handle body, a magazine for holding a series of fasteners and progressively advancing them to a predetermined driving location, a driving element movable in a predetermined first direction relative to said body and operable by such movement to drive a fastener at said location into a work piece, yielding means urging said driving element in said first direction-to drive the fastener, a backing structure mounted to said body and restrained against movement in said reverse direction relative to the body and taking the reactive thrust of said yielding means in a direction the reverse of said first direction, means forming a stop surface limiting the movement of said driving element by said yielding means in said first direction and transmitting the advancing force of said driving element to said magazine, means for retracting said driving element, and a pivotal connection between said magazine and said handle body mounting said handle body and said backing structure for recoiling movement in said reverse direction relative to said stop surface and relative to said magazine under the influence of said reactive thrust of the yield-ing means.

7. A fastening device as recited in claim 6, including means limiting the relative pivotal movement of said handle body and said magazine.

8. A fastening device as recited in claim 6, in which said magazine has a forward wall against which a fastener at said driving location is urged, said forward wall being mounted for said pivotal movement with the rest of the magazine.

9. A fastening device comprising means for holding a staple, a driving element movable in a predetermined first direction and operable by such movement to drive said staple into a work piece, yielding means urging said driving element in said first direction to drive the staple, a backing structure taking the reactive thrust of said yielding means in a direction the reverse of said first direction, means forming a stop surface limiting the movement of said driving element by said yielding means in said first direction, means for retracting said driving element, and means mounting said backing structure for recoiling movement in said reverse direction relative to said stop surface under the influence of said reactive thrust of the yielding means.

10. A fastening device comprising a handle body, a magazine for holding a series of staples and progressively advancing them to a predetermined driving location, a driving element movable in a predetermined first direction relative to said body and operable by such movement to drive a staple at said location into a Work piece, yielding means urging said driving element in said first direction to drive the staple, a backing structure mounted to said body and restrained against movement in said reverse direction realtive to the body and taking the reactive thrust of said yielding means in said reverse direction, means forming a stop surface limiting the movement of said driving element by said yielding means in said first direction and transmitting the advancing force of said driving element to said magazine, means for retracting said driving element, and means mounting said handle body and said backing structure for recoiling movement in said reverse direction relative to said stop surface and relative to said magazine under the influence of said reactive thrust of the yielding means.

References Cited in the file of this patent UNITED STATES PATENTS 2,080,130 Hansen May 11, 1937 2,659,083 Boroughs Nov. 17, 1953 2,671,215 Abrams Mar. 9, 1954 

1. A FASTENING DEVICE COMPRISING MEANS FOR HOLDING A FASTENER, A DRIVING ELEMENT MOVABLE IN A PREDETERMINED FIRST DIRECTION AND OPERABLE BY SUCH MOVEMENT TO DRIVE SAID FASTENER INTO A WORK PIECE, YIELDING MEANS URGING SAID DRIVING ELEMENT IN SAID FIRST DIRECTION TO DRIVE THE FASTENER, A BACKING STRUCTURE TAKING THE REACTIVE THRUST OF SAID YIELDING MEANS IN A DIRECTION THE REVERSE OF SAID FIRST DIRECTION, MEANS FORMING A STOP SURFACE LIMITING THE MOVEMENT OF SAID DRIVING ELEMENT BY SAID YIELDING MEANS IN SAID FIRST DIRECTION, MEANS FOR RETRACTING SAID DRIVING ELEMENT, AND MEANS MOUNTING SAID BACKING STRUCTURE FOR RECOILING MOVEMENT IN SAID REVERSE DIRECTION RELATIVE TO SAID STOP SURFACE UNDER THE INFLUENCE OF SAID REACTIVE THRUST OF THE YIELDING MEANS. 